• Cement
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• s.190
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• pp.32-38
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• 2011

콘크리트에서 알칼리골재반응은 내구성에 악 영향을 주는 일종의 암이라고 표현할 수 있다. 잠복기간이 길고, 균열이 나타나는 시기도 매우 오래 걸리기 때문이다. 이러한 현상이 1940 년대 알려지면서, 미국 ASTM에는 1950년에 모르타르봉 시험방법이, 1952년에 화학법이 각각 시험방법 규격으로 제정되었다. 국내에서는 한국도로교통연구원을 비롯한 전문연구기관 등에서 화학법 및 모르타르봉 방법으로 연구한 결과, 화학법에서는 일부 골재가 반응성이 있는 것으로 보고 되었으나, 모르타르봉 방법에서는 대상 골재에서 유해가능성이 낮은 것으로 보고되었다. 또한, 그동안은 구조물에서 알칼리골재반응에 의한 피해사례도 보고되지 않았고, 골재의 품질도 양호한 것으로 알려져 왔다. 그러나, 최근들어 서해안 고속도로 일부 구간에서 알칼리골재반응에 의한 포장노면에 균열 및 스폴링 등 심각한 피해사례가 보고되면서 국내에서도 관심이 높아지기 시작하였다. 특히 일본에서는 제 63회 시멘트기술대회 (2009년 5월 22일)에서 팽창기구의 재검토에 대한 이야기가 패널토의에서 제기되었고, 일부 시험방법의 이야기도 나왔다. 그동안의 골재는 현재의 규격만으로도 설명이 가능했는데, 최근의 골재들은 설명이 잘 안 되는 경우가 종종 있다는 이야기다. 이런 이야기들은 일본 지인들과 기술교류를 하면서 많은 이야기를 나누었고, 또한 우연히 문헌들을 독해하던 중 이런 이야기들을 경험한 문헌인 일본 태평양시벤트에서 발간되는 CEM'S 자료를 찾았기에 발췌 정리한 것이다.

• Food Engineering Progress
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• v.21 no.2
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• pp.167-173
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• 2017

Purple-fleshed potato powder (PFPP) was investigated to determine optimal mixing ratio with milk powder and dextrin to produce a ready-to-eat mashed potato powder. The rheological characteristics, color, and anthocyanin contents were studied at a different concentration of ingredients. The power-law model was applied to explain the mechanical spectra of mashed potatoes which represented the change in structure induced by different mixing ratios. Mixture design was used to obtain the experimental points used to establish the empirical models to describe the effects of each ingredient on the characteristic of the mashed potato. The results of mechanical spectra showed that both storage and loss moduli (G' and G'') were significantly influenced by PFPP and milk powder concentration. The power law parameters n' and n'' showed higher values for the mashed potato with a lower concentration of PFPP and a higher concentration of milk powder, which showed that the gel networks involved in the mashed potato were weaker. The optimum mixing ratio with the highest redness and anthocyanin content, while maintaining the rheological properties similar to the commercial mashed potato, was determined as PFPP:milk powder:dextrin = 90.49:4.86:4.65 (w/w). The proportions of PFPP and milk powder in the formulation significantly changed the characteristics of mashed potato, whereas no significant effect of dextrin was observed in this formulation.

• Journal of the Korean Geotechnical Society
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• v.40 no.4
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• pp.7-18
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• 2024

Because of their mineral composition, tire chips have very low thermal conductivity compared with natural geomaterials, leading to the use of sand-tire rubber mixtures in thermally insulating applications. However, systematic studies evaluating factors affecting the thermal conductivity of sand-tire rubber mixtures have been very limited. Thus, this study investigated the thermal conductivity of sand-tire rubber mixtures with varying size ratios and tire chip fractions according to the degree of saturation (S). Specimens were prepared in insulated cells, and thermal needle probe tests were performed. In addition, the contact angle and solid surface free energy of sand-tire rubber mixtures were investigated. The results of this study revealed that the thermal conductivity decreased with increasing tire chip fraction but increased with increasing water content (or S). However, the trend of increasing thermal conductivity with S varied with the tire chip fraction, and the specimens with tire chip fraction > 0.4 clearly showed a delayed increase in thermal conductivity with increasing S. This reflected that hydrophobic particles (tire chip) affected the dependency of thermal conductivity on S because of the delayed formation of capillary water bridges, which served as additional thermal conduction paths with increased moisture content.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.6
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• pp.327-334
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• 2002

Method of besoil analysis were difficult to be applied universally since the use and the source material of bedsoils are diverse from country to country. Korean Standard Methods for Bedsoil Analysis was developed to measure the particle and bulk density. Fifty-three samples for horticultural bedsoil and nine samples for paddy rice bedsoil in the current market were collected. Particle density was measured by electrical pyconometer with He gas, and bulk density by the sandbox method, free fall method, plunger compaction method, free fall and plunger method, and sample weight compaction method. While the use of glass pycnometer which measures particle density to fill blank space with water was inappropriate due to floating organic and calcined inorganic materials in the water, the electrical pycnometer with gas type was suitable considering speed and accuracy. For bulk density, the sandbox method recommended as European Standard Method was more reasonable in principle than other methods. However, this method requires expensive apparatus and intricate process. Plunger compaction method was proposed as standard method, since it had higher consistence with the sandbox method than other methods, as well as an advantage of easy and prompt measurement. Particle density of bedsoil ranged $1.48{\sim}2.67Mg\;m^{-3}$(mean $1.93Mg\;m^{-3}$) for horticultural bedsoil and $2.33{\sim}2.67Mg\;m^{-3}$ (mean $2.43Mg\;m^{-3}$) for paddy rice bedsoil by the electrical pycnometer with He gas. Bulk density of bedsoil ranged $0.11{\sim}0.40Mg\;m^{-3}$ (mean $0.22Mg\;m^{-3}$) for horticultural bedsoil and $0.84{\sim}1.26Mg\;m^{-3}$(mean $1.01Mg\;m^{-3}$) for paddy rice bedsoil by plunger compaction method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.4
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• pp.1405-1410
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• 2010

The purpose of this study is to evaluate the capability of representative existing methods through which OCR of clayey soils can be predicted utilizing PCPT data. The existing methods include Schmertmann method, Chen and Mayne method using pore water pressures measured immediately behind the cone base $u_2$, Lunne et al. method, and the latest Abu-Farsakh method. The lab. and in-situ test results, conducted in Incheon port area, were used for the study. The predicted OCR values from the methods were compared with the reference values estimated from laboratory oedometer test. Lunne et al.(k=0.5) method provided relatively better result while all the prediction methods underestimated OCR.

• Water for future
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• v.20 no.2
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• pp.161-168
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• 1987

The prediction of changes in the tidal regime due to the construction of a barrier in the Keum River was performed via one-dimensional numerical model. It is shown that a barrier in Mangwolri will lead to a small increase in the $ tidal range. The validity of this prediction is examined using the hydrodynamic analogy with AC circuit theory. Some of preliminary results are presented and discussed.

• Journal of Korea Fair Competition Federation
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• no.99
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• pp.16-21
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• 2003

서울총회는 합병, 역량강화, 규제산업에서의 경쟁법 집행, 분임토의(Breakout), 이행점검, 향후 작업계획 등 총 6개의 세션으로 구성할 계획인데, 이행점검 세션은 그 동안의 ICN에서의 논의 결과에 대한 회원국들의 이행상황을 점검하기 위해 서울총회에 신설된 것으로서 ICN을 논의 단계에서 실제 이행으로 한 단계 진전시키는 성과를 가져올 것으로 기대되는 한편, 공정거래위원회는 아시아 지역에서 최초로 개최되는 ICN 총회를 성공적으로 준비$\cdot$개최함으로써 그 동안 우리나라가 OECD 경쟁위원회 부의장국, ICN 가입작업반 의장국 등을 맡으면서 쌓아온 경쟁정책 분야에서의 국제적 위상을 더욱 제고함은 물론 합병 심사절차의 국가간 조화 등 ICN의 실질적인 논의에 적극 참여하여 우리 입장을 최대한 반영할 것이다.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 1993.07a
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• pp.90-97
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• 1993

매입과 준설공영를 할 때 발생하는 현탁물질의 문제는 수역 환경보존의 입장에서 공사관계자들에게 높은 관심을 보이고 있다. 그리고 이러한 현탁물질의 발생정도는 시공법, 공사규모, 주변의 지형과 흐름상장에 의하여 좌우되며 또한 현탁물질에 의한 영향은 현탁물질의 정도, 공사기간, 수역의 이용상태, 공사에 사용하고 있는 토사의 양, 입도분포, 저토의 특성(입경등)에 따라서 좌우된다. (중략)

• Korean Architects
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• no.7 s.267
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• pp.83-89
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• 1991

본협회는 지난달, 3천6백여 회원들이 한자리에 모인가운데 “21세기의 건축”의 나아갈 길을 밝히고 건축계의 발전을 도모하기 위한 ‘91 전국건축사대회의 일환으로 올바른 건축환경조성을 위해 건축관계법령과 제도의 개선을 모색하기 위한 ’건축관계법 개정(안)에 대한 토론회‘를 개최하였다. 본 협회 법제위원장인 한규봉회원의 진행으로 2개 과제로 나누어, 건설관계법의 근간을 이루는 건축법과 건축사법의 개정방향에 대해 심도있게 다룬 이번 토론회는 본협회 소속 회원들뿐 아니라 정부 및 건축관련인들의 지대한 관심 속에서 진행되었다. 본지는 이번 토론회에서 토의된 내용들을 정리, 주요내용을 요약, 발췌하여 게재한다.

• Journal of the Korean GEO-environmental Society
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• v.17 no.2
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• pp.13-22
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• 2016

Accurate settlement estimation of dredged soft soil deposits is significantly important to prevent potential disasters during land reclamation. An application of the non-linear finite strain consolidation theory is inevitable in dealing with a very soft ground formation such as dredged fill. In this paper, a series of the sedimentation-consolidation test, self-weight consolidation test and CRS test were conducted to clarify sedimentation and consolidation characteristics of dredged fill in the Songdo area, Incheon. In addition, the settlement of dredged fill was numerically simulated using the PSDDF program. The dredged soil obtained from the Songdo area was classified as low-compressible silt (ML) based on USCS (Unified Soil Classification System), and the final bulking factors were estimated to be 1.56 and 1.17 by Yano's method and the numerical simulation, respectively. This difference is attributable to relatively high reclaimed height and large permeability of dredged soil in this region.